#!/usr/bin/env node
//导出类

class Circle{
  constructor(r){
      this.#radius=r;
  }
  get diameter(){
    return 2 * this.#radius;
  }
  get area(){
    return Math.PI * this.#radius * this.#radius;

  }
  get circumference(){
    return 2* Math.PI * this.#radius;

  }

  #radius=0;

}
module.exports=Circle;
//注意radius，中英文分号
